 /*******************************************************************************
  * Copyright (c) 2004, 2006 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM - Initial API and implementation
  *******************************************************************************/
 package org.eclipse.ui.internal.ide.actions;

 import org.eclipse.jface.action.IAction;
 import org.eclipse.ui.actions.RetargetAction;

 /**
  * A specialization of RetargetAction that allows for specification of a default
  * handler when the active part does not supply one. Enablement of this
  * action is based on enablement of the handler, or enablement of the default
  * handler if no explicit handler is available.
  *
  * @since 3.1
  */
 public class RetargetActionWithDefault extends RetargetAction {

     private IAction defaultHandler;

     /**
      * Constructs a RetargetActionWithDefault with the given action id and text.
      *
      * @param actionID the retargetable action id
      * @param text the action's text, or <code>null</code> if there is no text
      */
     public RetargetActionWithDefault(String actionID, String text) {
         super(actionID, text);
     }

     /* (non-Javadoc)
      * Method declared on RetargetAction.
      */
     protected void setActionHandler(IAction newHandler) {
         super.setActionHandler(newHandler);
         // Only set the default handler after clearing the old handler above.
 // This triggers enablement updating on the default handler which
 // might be needed since the active part has changed.
 if (newHandler == null) {
             super.setActionHandler(defaultHandler);
         }
     }

     /**
      * Sets the default handler for this action.
      * @param handler An action handler, or <code>null</code>
      */
     public void setDefaultHandler(IAction handler) {
         this.defaultHandler = handler;
         if (getActionHandler() == null && handler != null) {
             super.setActionHandler(handler);
         }
     }
 }

